Electronic device and method of manufacturing the same

ABSTRACT

A memory card wherein a substrate is affixed to a cap is formed without the projection of substrate edges from a back surface of the cap. The memory card includes a substrate having a sealing member bonded to a recess in the cap. By utilizing a difference in thermal expansion coefficient between the sealing member and the substrate, the substrate is warped so that its central portion projects away from the cap. The shallow recess is deeper than the sum of the thickness of the substrate and the thickness of an adhesive for bonding the substrate to the bottom of the shallow recess, whereby peripheral edges of the substrate retract into the shallow recess without projecting from the back surface of the cap. The cap is shaped as a card several millimeters thick. A memory chip and control chip are incorporated in the sealing member.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. application Ser. No.10/466,428 filed on Jul. 16, 2003, and claims priority fromPCT/JP01/00775 filed on Feb. 2, 2001, the entire disclosure of which isincorporated herein by reference.

FIELD OF ART

The present invention relates to an electronic device and a method ofmanufacturing the same. For example, the invention is concerned with atechnique applicable effectively to the fabrication of a memory cardwhich incorporates a semiconductor chip with an IC (integrated circuit)built into a thin card.

BACKGROUND ART

As storage mediums used in digital cameras and audio players there areused memory cards called, for example, SD (Secure Digital) Card, MemoryStick, and Multi Media Card. The memory cards are characterized by beingas thin as 1.4 to 3 mm or so. Multi Media Card is a generic term formemory cards formed in accordance with a standard published by MultiMedia Card Association (MMCA).

In Japanese Published Unexamined Patent Application No. 2000-236043there is described a warp preventing technique for a COB (chip on board)package which is assembled to a chip card. In this publication there isdescribed a structural example in which a COB package having a sealingmember on one surface of a printed circuit board is bonded to areceptacle portion which is a recess formed in one surface of a cardbody. Reference is also here made to Japanese Published UnexaminedPatent Application No. Hei 11(1999)-45959 which describes a techniquefor preventing the warp of a COB substrate.

Further, in Japanese Published Unexamined Patent Application No. Hei8(1996)-156470 there is described a technique for preventing theoccurrence of breakage in the vicinity of a tip corner of an IC mountingportion upon imposition of a flexural deformation on an IC card. In thispublication it is described that when an IC module is bonded with anadhesive into a hole formed in a card substrate, if the IC module isforced into the hole, the adhesive will protrude to the exterior of thehole.

The applicant in the present case has also developed a small-sizedmemory card called a multi-media card. As shown in FIG. 29(a), thismemory card, which is indicated at 1, comprises a card-like cap 2 and asubstrate 6, the substrate 6 having a sealing member 5 which is affixedthrough an adhesive 4 to a stepped recess 3 formed in one surface of thecap 2. The substrate 6 serves as a wiring substrate, and within thesealing member 5 are present plural semiconductor chips (not shown)fixed to the substrate 6 and wires for electrically connectingelectrodes formed on the semiconductor chips with wiring lines formed onthe substrate.

The sealing member 5 is formed of an insulating resin by transfermolding to improve the productivity. The substrate 6 is formed by aglass fabric-based epoxy resin board. The semiconductor chips are formedof silicon (Si) and the sealing member 5 is formed of an epoxy resin.

A surface of the memory card 1 is located on a back surface 6 b side ofthe substrate 6 affixed to a back surface 2 b of the cap 2. The surfaceportion of the cap 2 exposed framewise around the substrate 6 is theback surface 2 b.

Where required, a film or the like having predetermined printedcharacters or the like is affixed to the surface 2 a of the cap 2 or theback surface 6 b of the substrate 6.

It has turned out that there sometimes occurs the following defect inmanufacturing the memory card 1. As shown in FIG. 29(b), when thesubstrate 6 is bonded to the cap 2 with use of the adhesive 4, the backsurface 6 b of the substrate 5 warps in a depressed state and endportions of the substrate 6 project from an upper surface of the cap 2.

This is caused by a heat distortion based on a difference in thermalexpansion coefficient among the substrate 6, the semiconductor chips andsealing member 5 which occurs at the time of radiation of heat aftertransfer molding and heat curing of the molding resin.

The thermal expansion coefficient of the glass fabric-based epoxy resinboard which constitutes the substrate 6 is about 1.3 to 1.6×10⁻⁵/° C.,that of Si which forms the semiconductor chips is about 3.0×10⁻⁶/° C.,and that of the epoxy resin which forms the sealing member 5 is about 8to 16×10⁻⁶/° C. As a result, after transfer molding, the sealing member5 projects toward a surface 6 a of the substrate 6 and the back surface6 b of the substrate 6 warps in a centrally depressed state, as shown inFIG. 29(b).

Due to such a depressed warp phenomenon of the back surface 6 b of thesubstrate 6, even if both ends of the substrate 6 are affixed uniformlyto the cap 2, they project (projection quantity “a”) from the backsurface 2 b (upper surface in FIG. 29) of the cap 2. When the memorycard 1 is to be used, it is inserted into a slot of a digital camera orthe like, but if the projection quantity “a” is large, the projectingportion will be caught in the slot and hence it will become impossibleto insert the memory card 1 into the slot. The projection quantity “a”differs depending on the size of the substrate 6, but if the substratesize is, for example, 32 mm long, 23 mm wide, and 1.4 mm thick, theprojection quantity “a” is as large as about 150 to 200 μm.

If the substrate 6 is affixed to the cap 2 in an offset manner, an endportion of the substrate warps to a larger extent, as shown in FIG.29(c). For example, where the thickness of the cap 2 is 1.4 mm, a totalthickness “c” is as large as 1.7 mm.

Further, when the substrate 6 is affixed to the cap 2 through theadhesive 4, the adhesive 4 protrudes like arrows from between substrateends and peripheral edges of the recess 3 of the cap 2, thereby formingraised portions 7. Such a rising phenomenon of the adhesive results in astructure in which an outer surface of the substrate 6 warps in adepressed state. In view of this structure it has turned out that whenthe substrate 6 is pushed against the cap 2, the warp acts to push outthe adhesive 4 present centrally of the recess 3 toward the peripheraledges of the substrate 6 and that therefore the adhesive risingphenomenon becomes easier to occur.

FIG. 30 is a three-dimensional representation of results obtained bymeasuring a state of warp of a substrate used in a memory cardcommercially available from A company. In the same figure, longitudinalgraduations 0 to 32 are in mm and transverse graduations 0 to 20 arealso in mm. Graduations 0 to 1.6 represent the thickness (height) fromthe surface of the cap and the unit thereof is mm. Also in this example,a central part of a substrate is depressed. Further, it is seen thatperipheral edge portions of the substrate project beyond the capthickness of 1.4 mm.

FIG. 31 represents results of having measured a state of warp of asubstrate used in a memory card available commercially from B company,in three-dimensions after image processing. Like the structure shown inFIG. 30, a central part of the substrate is depressed. It is seen thatperipheral edge portions of the substrate project beyond the capthickness of 1.4 mm.

FIG. 32 represents results of having measured a state of warp of asubstrate used in a memory card available commercially from C company,in three-dimensions after image processing. In the same figure there isshown an arcuate surface which warps longitudinally of the memory cardand projects centrally. Also in this warped state peripheral edges ofthe substrate project beyond the cap thickness of 1.4 mm. Also in thisexample it is seen that side edges located near the central part of thesubstrate further project from the cap.

It is an object of the present invention to provide an electronic deviceof a structure in which a substrate is affixed through an adhesive to arecess formed in a back surface of a cap, with substrate edges being notprojected from the back surface of the cap, as well as a method ofmanufacturing the electronic device.

It is another object of the present invention to provide a memory cardof a structure in which a substrate is affixed through an adhesive to arecess formed in a back surface of a cap, with substrate edges being notprojected from the back surface of the cap, as well as a method ofmanufacturing the memory card.

It is a further object of the present invention to provide an electronicdevice of a structure in which a substrate is affixed through anadhesive to a recess formed in a back surface of a cap and in which araised portion caused by flowing out of the adhesive does not occur onthe back surface of the cap, as well as a method of manufacturing theelectronic device.

It is a still further object of the present invention to provide amemory card of a structure in which a substrate is affixed to a backsurface of a cap through an adhesive and in which a raised portioncaused by flowing out of the adhesive does not occur on the back surfaceof the cap, as well as a method of manufacturing the memory card.

The above and other objects and novel features of the present inventionwill become apparent from the following description and the accompanyingdrawings.

DISCLOSURE OF THE INVENTION

Typical modes of the present invention as disclosed herein will beoutlined below.

(1) An electronic device comprising a substrate which is a wiringsubstrate, one or more semiconductor chips fixed to a surface of thesubstrate and having predetermined electrodes connected electrically towiring lines formed on the substrate, a sealing member formed of aninsulating resin on the surface of the substrate to cover apredetermined area including the semiconductor chip(s), and a cap havinga recess formed in a back surface thereof which recess permits thesubstrate and the sealing member to be received therein, the sealingmember on the substrate being received in the recess of the cap and thesubstrate being affixed to the cap through the adhesive, whereinperipheral edges of the substrate do not project from the recess to theback surface of the cap, and a central portion of the substrate warps soas to project in a direction away from the cap.

Such an electronic device (memory card) is fabricated, for example, by amethod comprising the steps of fixing semiconductor chips (a memory chipand a control chip) to a surface of a substrate which is a wiringsubstrate; connecting electrodes formed on the semiconductor chips andwiring lines formed on the substrate with each other electrically usinga connecting means; molding a predetermined area including thesemiconductor chips with an insulating resin to form a sealing memberwhich covers the semiconductor chips and the connecting means; placingand pushing the sealing member and the substrate portion into andagainst a recess of a cap, the recess being formed in a back surface ofthe cap so as to permit the substrate and the sealing member to bereceived therein, and bonding the substrate to the cap through anadhesive put into the recess; and allowing the adhesive to cure, whereina thermal expansion coefficient of a material which forms the substrateand that of a material which forms the sealing member are selected sothat the substrate after molding warps in a centrally projected statetoward a back surface of the substrate, and thereafter the substrate isfixed to the cap through the adhesive, peripheral edges of the substratebeing not projected from the recess to the back surface of the cap, andthe substrate being centrally warped so as to project in a directionaway from the cap.

According to the above means (1):

(a) peripheral edges of the substrate do not project from the recess tothe back surface side of the cap. Therefore, in the case of a memorycard, there does not occur such an inconvenience as the memory cardcannot be inserted into a slot of a digital camera or the like.

(b) The surface side of the substrate with the sealing member formedthereon is depressed, so that when the substrate is pushed against thecap so as to be affixed to the cap through an adhesive, the peripheraledges of the substrate surround the adhesive and act to move theadhesive inwards, so that it is possible to prevent the adhesive fromleaking out to the back side of the cap from the peripheral edges of thesubstrate. Therefore, it is possible to prevent the occurrence of amemory card not being insertable into a slot of a digital camera or thelike due to leakage of the adhesive.

(c) With the above effects (a) and (b), it is possible to improve thedimensional accuracy of the memory card and prevent the formation of aprojection and leakage of the adhesive, whereby the quality becomesstable. As a result, the manufacturing yield is improved, and reductionsin product cost can be attained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exaggerated schematic sectional view of a memory cardaccording to an embodiment (first embodiment) of the present invention;

FIG. 2 is a plan view showing a surface of the memory card;

FIG. 3 is a bottom view showing a back surface of the memory card;

FIG. 4 is a sectional view taken along line A-A in FIG. 3;

FIG. 5 is a three-dimensional diagram based on measurement results,showing a frame-like cap portion at the back surface of the memory cardand a state of warp of a back surface of a substrate;

FIG. 6 is a numeric table showing a portion of data which underlie thethree-dimensional diagram of FIG. 5;

FIG. 7 is a partial three-dimensional diagram showing a state of warp ofthe substrate back surface, including a front side of thethree-dimensional diagram of FIG. 5;

FIG. 8 is a partial three-dimensional diagram showing a state of warp ofthe substrate back surface, including a rear side of thethree-dimensional diagram of FIG. 5;

FIG. 9 is a partial three-dimensional diagram showing a state of warp ofthe substrate back surface, including terminal portions of thethree-dimensional diagram of FIG. 5;

FIG. 10 is a graph showing a difference in distance “r” from a virtualreference plane due to a difference of resin used in a sealing member inthe memory card of the first embodiment;

FIG. 11 is a schematic diagram showing states of manufacturing steps inmanufacturing the memory card of the first embodiment;

FIG. 12 is a plan view of the substrate with semiconductor chips mountedthereon in manufacturing the memory card of the first embodiment;

FIG. 13 is a schematic sectional view of the substrate after completionof the mounting of semiconductor chips, wire bonding and the formationof a sealing member in manufacturing the memory card of the firstembodiment;

FIG. 14 is a plan view showing a surface of the substrate with a sealingmember formed thereon in manufacturing the memory card of the firstembodiment;

FIG. 15 is a bottom view showing a back surface of the substrate formedwith the sealing member in manufacturing the memory card of the firstembodiment;

FIG. 16 is a side view of the substrate formed with the sealing memberin manufacturing the memory card of the first embodiment;

FIG. 17 is a plan view showing a back surface of a cap used inmanufacturing the memory card of the first embodiment;

FIG. 18 is a sectional view taken along line B-B in FIG. 17;

FIG. 19 is a plan view of a substrate after the mounting ofsemiconductor chips thereon in another example of a memory card in thememory card manufacturing according to the first embodiment;

FIG. 20 is a schematic sectional view of the substrate after themounting of semiconductor chips, wire bonding and the formation of asealing member in the another example of the memory chip in the memorycard manufacturing according to the first embodiment;

FIG. 21 is a schematic sectional view of a substrate after the mountingof semiconductor chips, wire bonding and the formation of a sealingmember in the memory card manufacturing according to the firstembodiment;

FIG. 22 is a plan view showing a back surface of a cap used in a memorycard according to another embodiment (second embodiment) of the presentinvention;

FIG. 23 is an exaggerated schematic sectional view of a memory cardaccording to a further embodiment (third embodiment) of the presentinvention;

FIG. 24 is a bottom view showing a back surface of a substrate having asealing member used in a memory card according to a still furtherembodiment (fourth embodiment) of the present invention;

FIG. 25 is a plan view showing a back surface of a cap used in a memorycard according to a still further embodiment (fifth embodiment) of thepresent invention;

FIG. 26 is a schematic sectional view showing in what state a substrateis affixed to the cap in the memory card of the fifth embodiment;

FIG. 27 is a plan view showing a back surface of a cap used in a memorycard according to a still further embodiment (sixth embodiment) of thepresent invention;

FIG. 28 is a sectional view taken alone line C-C in FIG. 27;

FIG. 29 is a schematic sectional view showing a memory card which theapplicant in the present case has studied prior to the present inventionand also showing defective states in assembly;

FIG. 30 is a three-dimensional diagram based on results of havingmeasured a state of warp of a substrate used in a memory card availablecommercially from A company;

FIG. 31 is a three-dimensional diagram based on results of havingmeasured a state of warp of a substrate used in a memory card availablecommercially from B company; and

FIG. 32 is a three-dimensional diagram based on results of havingmeasured a state of warp of a substrate used in a memory card availablecommercially from C company.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described in detailhereinunder with reference to the accompanying drawings. In all of thedrawings for illustrating the embodiments, constituent portions havingthe same functions are identified by like reference numerals, andrepeated explanations thereof will be omitted.

FIRST EMBODIMENT

In this first embodiment the present invention is applied to, forexample, a memory card (e.g., a multi-media card having a capacity aslarge as 64 MB) as an electronic device having a memory chip and acontrol chip for controlling the memory chip.

FIGS. 1 to 20 are concerned with the manufacture of a memory cardaccording to an embodiment (first embodiment) of the present invention,of which FIGS. 1 to 4 are concerned with the structure of the memorycard, FIGS. 5 to 9 illustrate a three-dimensional representation showinga state of warp of a substrate on a back surface side of the memorycard, as well as data which underlie the three-dimensionalrepresentation, FIG. 10 is a graph showing a difference in distance “r”from a virtual reference plane due to a difference of resin used in asealing member, and FIGS. 11 to 20 are related to the manufacture of thememory card.

In appearance, the memory card, indicated at 1, is in the form of a thinplate (card), as shown in FIGS. 2 to 4.

FIG. 2 is a plan view showing a surface of the memory card, FIG. 3 is abottom view showing a back surface of the memory card, and FIG. 4 is aside view taken along line A-A in FIG. 3. Further, FIG. 1 is anexaggerated schematic sectional view of the memory card.

As shown in FIGS. 1 to 4, the memory card 1 of this first embodiment ismade up of a card-like cap 2 and a substrate 6 having a sealing member5, the substrate 6 being affixed through an adhesive 4 to a steppedrecess 3 formed in one surface of the cap 2. An exposed flat surface ofthe cap 2 is a surface 2 a which is a surface side of the memory card 1and to which is affixed a seal 9 a describing functions and productcontents. An exposed back surface 6 b of the substrate 6 is a backsurface side of the memory card 1.

The substrate 6 has a wiring substrate structure. One or pluralsemiconductor chips (not shown) are mounted on a surface 6 a of thesubstrate 6, and electrodes formed on the semiconductor chip(s) andwiring lines formed on the substrate 6 are connected together throughconductive wires.

The semiconductor chip(s) and the wires are covered with the sealingmember 5 which is formed of an insulating resin by transfer molding. Forexample, the substrate 6 is a glass fabric-based epoxy resin wiringboard having a thickness of 0.33 mm, a width of 21 mm and a length of 30mm (in the present invention, as the glass fabric-based epoxy resinwiring board there may be used one having a thermal expansioncoefficient of 1.3×10⁻⁵/° C. to 1.6×10⁻⁵/° C.). The substrate 6, whichis rectangular (quadrangular), is obliquely cut off at one cornerthereof to afford a slant face, as shown in FIGS. 14 and 15. As shown inFIG. 3, external electrode terminals 8 b formed on the back surface 6 bof the substrate 6 are exposed to the back surface of the memory card 1.When the memory card 1 is inserted into a slot of a digital camera, theexternal electrode terminals 8 b come into contact with electrodeterminals formed within the slot. As shown in FIG. 14, electrodeterminals 8 a for inspection corresponding to the external electrodeterminals 8 b, as well as electrode terminals 8 c and 8 d forinspection, are provided on the surface 6 a of the substrate 6.

As shown also in FIGS. 17 and 18, the cap 2 is constituted by a resincase (e.g., PPE: polyphenyl ether) and is, for example, 32 mm long, 23mm wide, and 1.4 mm thick. In a back surface 2 b of the cap 2 is formeda stepped recess 3. The stepped recess 3 comprises a shallow recess 3 afor fitting therein of the substrate portion and a deep recess 3 b forfitting therein of the sealing member 5, the deep recess 3 b beingformed in a bottom of the shallow recess 3 a. The substrate 6 is in arectangular shape (30 mm long by 21 mm wide) with one corner thereof cutoff obliquely and therefore the size of the shallow recess 3 a is alittle larger than that of the rectangular shape. A clearance betweenperipheral edges of the substrate 6 and the shallow recess 3 a in afitted state of the substrate into the recess is 0.15 mm or so.

The deep recess 3 b is for fitting therein of the sealing member 5 whichis formed on the surface 6 a of the substrate 6. Given that the heightof the sealing member 5 is about 0.64 mm, the depth of the deep recess 3b is, for example, 0.71 mm to create a clearance of 70 μm. An adhesivedoes not flow smoothly unless there is a space of about 40 μm in heightthough this differs depending on the type of the adhesive used. For thisreason the clearance is set at 70 μm in this first embodiment. Apredetermined clearance is formed also between an inner peripherysurface of the deep recess 3 b and an outer periphery surface of thesealing member 5 so that the adhesive 4 can flow from the deep recess 3b to the shallow recess 3 a.

As shown in FIG. 1, one of the features of the memory card of this firstembodiment resides in a structure such that edges of the substrate 6 areretracted into the shallow recess 3 a and do not project to theexterior. Therefore, the height from an upper surface of the sealingmember 5 formed on a main surface of the substrate 6, i.e., from asurface of the sealing member 5 close to the bottom of the deep recess 3b in the cap 2, to the back surface of the substrate 6 at peripheraledges of the substrate, should be within the stepped recess of the cap2. In other words, the height from the upper surface of the sealingmember 5 to the back surface of the substrate 6 at peripheral edges ofthe substrate should be lower than the height from the bottom of thedeep recess 3 b in the cap 2 to the back surface 2 b of the cap. Bysatisfying this morphological requirement it is possible to realize ashape wherein peripheral edges of the substrate 6 are received withinthe shallow recess 3 a. The depth of the shallow recess 3 a is largerthan the sum of the thickness of the substrate 6 and the thickness ofthe adhesive 4 which is for affixing the substrate to the recess bottom.For example, if the thickness of the substrate 6 is 0.38 mm, the depthof the shallow recess 3 a is set at 0.28 mm taking the thickness of theadhesive 4 also into account, to give a difference of 0.05 mm from thecase where the adhesive 4 is not present. In this way, as shown in FIG.1, the memory card 1 is fabricated so that a difference “f” in heightbetween the back surface 2 b of the cap 2 and an upper edge of an end ofthe substrate 6 is, for example, 0 to 0.05 mm.

It is important that a projecting height “g” of the substrate from theback surface 2 b of the cap 2 be within a specified range, e.g., 0.15 mmor less.

In this first embodiment, in order for edges of the substrate 6 to beretracted inside the recess 3 a and not to project to the exterior,there is adopted such a warped structure as shown in FIG. 1 in which thesubstrate 6 is warped so that its back surface 6 b projects centrallyand in which peripheral edges of the substrate surface 6 a is put incontact with the bottom of the shallow recess 3 a. For this warpedstructure it is effective to select an appropriate thermal expansioncoefficient of the material which forms the substrate 6 and that of thematerial which forms the sealing member 5.

FIG. 10 is a graph obtained from experiments conducted by the presentinventor. In the structure of this first embodiment, the warp of thesubstrate 6 was checked using as the substrate 6 a glass fabric-basedepoxy resin board having a thermal expansion coefficient of 1.5×10⁻⁵/°C. and while changing the type of resin which constitutes the sealingmember 5. Among resins available commercially, resins A to F wereselected as resins capable of achieving this purpose. The selectedresins are different in thermal expansion coefficient α due to adifference in their components.

As shown in FIG. 1, if a projecting height of the substrate 6 from aperipheral edge of its back surface 6 b, in other words, the distancefrom a virtual reference plane to a peripheral edge on the back surface6 b side of the substrate, the virtual reference plane corresponding toa central surface portion of the substrate back surface 6 b, is assumedto be “r,” then in the case of resin A having a thermal expansioncoefficient of 8×10⁻⁶/° C. the substrate 6 warps in a minus (−)direction, that is, the back surface 6 b is depressed, whereas in thecase of resin B having a thermal expansion coefficient of 12×10⁻⁶/° C.the substrate 6 warps in a plus (+) direction, i.e., the surface 6 a isdepressed, mainly under the influence of the thermal expansioncoefficient and cure shrinkage of the resin. In the case of resins C toF which are still larger in thermal expansion coefficient than resin B,the larger the thermal expansion coefficient, the larger the warp in theplus direction, i.e., the larger the depression of the surface 6 a ofthe substrate 6, and the larger the distance “r.”

In this first embodiment a maximum value of the distance “r” is set at0.2 mm for example so that the projecting height “g” of the back surface6 b of the substrate 6 after assembly is within the specified range. Thevalue of 0.2 mm is a value determined while taking variations inthickness of the adhesive 4 into account. If a constant thickness of theadhesive 4 is ensured, the maximum value of the distance “r” will notalways be limited to 0.2 mm.

As an example, therefore, it is assumed that a resin which permits thedistance “r” to be in the range of 0.2 mm>r≧0 is employable and that inthe present invention there are used such resins B to E as shown in FIG.10. However, even if the type of resin fed increases, such increasedtypes of resins are also employable if they are in the range from about9×10⁻⁶/° C. to about 16×10⁻⁶/° C. in thermal expansion coefficient.

It goes without saying that the setting of the distance “r” is changedif the specified value changes and that if there is a request for aproduct not falling under the specified range, there is selected adistance “r” which meets the request.

Resin B is used in this first embodiment. FIG. 5 is a three-dimensionaldiagram obtained by measuring flatness on the back surface side of thememory card 1 which has been fabricated using resin B. In the samefigure there are shown flatness of the frame-like back surface 2 b ofthe cap 2 and that of the back surface 6 b of the substrate 6 which islocated inside the back surface 2 b and which has undergone a plus warp.From a front left to a rear left in FIG. 5 there is shown the backsurface 2 b of the cap nearly corresponding to the height of 1.4 mm, andan edge of the substrate back surface 6 b located inside the cap backsurface 2 b is lower than 1.4 mm, while a central portion of thesubstrate back surface 6 b is as high as about 1.48 to 1.49 mm. FIG. 6is a numeric table showing a portion of data which underlie thethree-dimensional diagram of FIG. 5. As shown in FIG. 6, the height ofthe back surface 6 b at a peripheral edge of the substrate 6 takes avalue smaller than 1.4 mm, and the closer to the inside, the larger thenumerical value, with values of 1.48 to 1.49 mm being found in thecentral portion. The basic data represent a portion of such numericalvalues and underlie the three-dimensional diagram of FIG. 5.

FIGS. 7 to 9 each illustrate a part of the three-dimensional diagram, ofwhich FIG. 7 illustrates a state of warp of the substrate, including afront side in FIG. 5, FIG. 8 illustrates a state of warp of the backsurface of the substrate, including a rear side of the three-dimensionaldiagram of FIG. 5, and FIG. 9 illustrates a state of warp of thesubstrate back surface, including terminal portions.

Features of the warp of the substrate back surface 6 b in the memorycard 1 of this first embodiment can be expressed in terms of severalexpressive forms as follows:

{circle around (1)} The central portion of the substrate projects higherthan side portions of the substrate.

{circle around (2)} The central portion of the substrate projects higherthan corner portions of the substrate.

{circle around (3)} If the substrate is divided into three equalportions lengthwise and crosswise and if a central portion and portionsspreading around the central portion are assumed to be a central areaand peripheral areas, respectively, a highest projecting portion of thecentral area is higher than highest projecting portions respectively ofthe peripheral areas.

{circle around (4)} If the substrate is divided into three equalportions lengthwise and crosswise and if a central portion and portionsspreading around the central portion are assumed to be a central areaand peripheral areas, respectively, a lowest projecting portion in thecentral area projects higher than a highest peripheral edge portion ofthe substrate.

{circle around (5)} If the substrate is divided into three equalportions lengthwise and crosswise and if a central portion and portionsspreading around the central portion are assumed to be a central areaand peripheral areas, respectively, a mean value of projecting heightsin the central area is larger than a mean value of projecting heights inthe peripheral areas.

Next, with reference to FIGS. 11(a) to 11(d), the following descriptionis provided about how to fabricate the memory card 1 constructed asabove. FIG. 11 is a schematic diagram showing states of the memory cardmanufacturing steps. ease amend the first full paragraph on page 26 asfollows:

As shown in FIG. 11(a), there is provided a substrate 6 constituted by aglass fabric-based epoxy resin board having a thermal expansioncoefficient of 1.5×10⁻⁵/° C. which has already been described. Then,semiconductor chips 15 are fixed to a surface 6 a of the substrate 6. Asthe semiconductor chips 15, there are used a memory chip 15 a and acontrol chip 15 b for controlling the memory chip 15 a. Thereafter,electrodes (not shown) on each semiconductor chip and wiring lines (notshown) formed on the surface 6 a of the substrate 6 are connectedtogether electrically through conductive wires 16. There may be usedanother means for connecting the electrodes with the wiring lines.

Next, as shown in FIG. 11(b), a sealing member 5 is formed on thesurface 6 a side of the substrate 6 by means of a conventional transfermolding machine. For the sealing member 5 there is used resin B having athermal expansion coefficient of 12×10⁻⁶/° C. (Si) in order to let thesubstrate 6 warp so that its surface 6 a is depressed, as noted earlierand as shown in FIG. 11(b). The resin B is an epoxy resin. After thetransfer molding, due to a difference in thermal expansion coefficientbetween the sealing member 5 and the substrate 6, the substrate 6assumes a warped shape (a plus warp structure) so as to centrallyproject in the direction of its back surface 6 b, including in thestrict sense the presence of the semiconductor chips 15 formed ofsilicon and fixed to the surface 6 a of the substrate 6.

As a result, the distance “r” based on the warp becomes 0.1 mm or so.Since the sealing member 5 is formed by transfer molding, not only thedimensional accuracy of the sealing member is high,. but also theproductivity is high and it is possible to reduce the cost for formingthe sealing member.

Next, as shown in FIG. 11(c), the cap 2 is provided and is placed sothat its back surface 2 b is positioned up. Thereafter, the adhesive 4is fed into the recess 3 under a highly accurate quantitative controlusing a dispenser. This quantitative control for the adhesive 4 isimportant for preventing leakage of the adhesive 4.

Then, as shown in FIG. 11(c), the substrate 6 is positioned with respectto the cap 2 so that the sealing member 5 lies on the lower surface sideof the substrate, and is pushed against the cap so that the sealingmember 5 and the substrate 6 are fitted in the recess 3. At this time,the adhesive 4 present in the recess 3 of the cap 2 tends to spread witha pressing force exerted thereon from a lower surface of the sealingmember 5, but bonding is effected in such a manner that the adhesive 4which spreads from the deep recess 3 b toward the shallow recess 3 a isreceived in the interior of the recess 3, because the amount of theadhesive 4 is set appropriate and the substrate 6 warps arcuately sothat its peripheral edges hang down. Therefore, as shown in FIG. 11(d),in a most appropriately controlled state of the amount of adhesive 4fed, the adhesive 4 lies within the range of the warped surface 6 a ofthe substrate 6 and does not leak to the exterior beyond the peripheraledges of the substrate 6. Consequently, such a raised portion 7 as shownin FIG. 29(d) is no longer formed. After the substrate 6 has beenaffixed to the cap 2, there is performed a curing treatment for theadhesive 4.

In this way, as shown in FIG. 11(d), there can be fabricated a memorycard 1 (an electronic device) in which peripheral edges of the substrate6 do not project from the recess 3 toward the back surface 2 b of thecap 2 and in which a central portion of the substrate 6 warps so as toproject in a direction away from the cap 2. Further, the projectingheight “g” of the back surface 6 b of the substrate 6 from the backsurface 2 b of the cap 2 is, for example, about 1.490 mm or so,including 1.492, or less, as shown in FIG. 6, thus satisfying thespecified range.

Thereafter, a seal 9 a is affixed to the surface 2 a of the cap 2 tofabricate the memory card 1 shown in FIGS. 2 to 4.

FIGS. 12 and 13 show a concrete example of the memory card of the firstembodiment fabricated as above, of which FIG. 12 is a plan view of thesubstrate after the mounting of semiconductor chips thereon and FIG. 13is a schematic sectional view of the substrate after the mounting ofsemiconductor chips, wire bonding and the formation of a sealing memberin the manufacture of the memory card.

The surface 6 a of the substrate 6 is shown in FIG. 12, with the memorychip 15 a and the control chip 15 b being fixed thereto. Though notdescribed with reference marks, wiring lines of predetermined patternsare formed on the surface 6 a.

After the semiconductor chips 15 have been fixed to the substrate 6,electrodes (not shown) on the semiconductor chips 15 and wiring lines onthe surface 6 a are electrically connected with each other through wires16. A sealing member 5 is formed in the area of the predeterminedsurface 6 a including the semiconductor chips 15 and the wires 16. Inorder to lower the height of the surface of the sealing member 5 fromthe substrate 6, a recess may be formed in the surface 6 a of thesubstrate 6 and the semiconductor chips 15 may be fixed to the recess.

FIGS. 19 and 20 show a further concrete example of the memory card ofthe first embodiment fabricated as above, of which FIG. 19 is a planview of the substrate after the mounting of semiconductor chips and FIG.20 is a schematic sectional view of the substrate after the mounting ofsemiconductor chips, wire bonding and the formation of a sealing memberin the manufacture of the memory card.

FIG. 19 shows the surface 6 a of the substrate 6, with memory chips 15 aand a control chip 15 b being fixed thereto. In this example, as isshown more clearly in FIG. 20, memory chips 15 a are fixed stackedly intwo stages to the substrate 6. In this example, as shown in FIG. 19,after a first memory chip 15 a is mounted on the substrate 6, a secondmemory chip 15 a is superimposed and fixed onto the first memory chip 15a in a displaced state. Then, as shown in FIG. 20, electrodes formed onexposed surfaces of the first and second memory chips 15 a and wiringlines formed on the substrate 6 are electrically connected with eachother through wires 16. According to this example there can be attaineda still larger memory capacity. This example is the same as the exampleshown in FIGS. 12 and 13 except that the semiconductor chip fixingmethod and the wire bonding method adopted in this example are differentfrom those adopted in the example of FIGS. 12 and 13.

As shown in FIG. 21, the structure involving the above two-stage fixingof memory chips 15 a may be designed such that a recess 20 is formed inthe surface 6 a of the substrate 6, the first memory chip 15 a is fixedto the bottom of the recess, and the second memory chip 15 a is fixedonto the first memory chip 15 a. By so doing, it is possible to diminishan increase in height of the sealing member 5. In this case, moreover,by adopting a conventional wire lowering technique, it is possible tomake the height of the sealing member equal to that of the sealingmember formed in a single-stage fixing of memory chip to the substrate.

The following effects are obtained by this first embodiment.

(1) The shallow recess 3 a is formed more deeply than the sum of thethickness of the substrate 6 and that of the adhesive 4 which is forbonding the substrate 6 to the bottom of the recess 3, and a thermalexpansion coefficient of the material which forms the substrate 6 andthat of the material which forms the sealing member 5 are selectedappropriately so that the substrate 6 is depressed on its surface 6 aside with the sealing member 5 formed thereon and is projected arcuatelyon its back surface 6 b side. Therefore, the peripheral edges of thesubstrate 6 do not project from the recess (shallow recess 3 a) to theback surface 2 b side of the cap 2. Thus, such an inconvenience as thememory card 1 being unable to be inserted into a slot of a digitalcamera or the like does not occur.

(2) The substrate 5 is depressed on its surface 6 a side with thesealing member 5 formed thereon, so when the substrate 6 is pushedagainst the cap 2 at the time of it being affixed to the cap with use ofthe adhesive 4, the peripheral edges of the substrate surround theadhesive 4 and act to move the adhesive inwards, whereby it is possibleto prevent the adhesive 4 from leaking to the back surface 2 b side ofthe cap from the peripheral edges of the substrate 6. Consequently,there does not occur such an inconvenience as the memory card 1 beingunable to be inserted into a slot of a digital camera or the like whichis caused by leakage of the adhesive 4.

(3) Since the adhesive is positioned inside the peripheral edges of thesubstrate, the peripheral edges of the substrate do not project to theback surface side of the cap from the interior of the shallow recess ofthe cap.

(4) Since a thermal expansion coefficient of the substrate 6 and that ofthe sealing member 5 are selected appropriately and the degree of thesubstrate warp described above is selected to a predetermined value, thethickness of the memory card 1 also conforms to the specified range.

(5) Through the above effects (1) to (4) the dimensional accuracy of thememory card 1 is improved and it is possible to prevent the formation ofa projection or a raised portion of the adhesive 4, so that the qualityof the memory card 1 becomes stable and the manufacturing yield isimproved, thus permitting the reduction of product costs.

(6) In the construction wherein memory chips are stacked in multiplestages on the substrate, it is possible to attain a large memorycapacity. Moreover, the construction wherein semiconductor chips otherthan memory chips are stacked in multiple stages is suitable also forthe attainment of various functions.

(7) According to the construction wherein a recess is formed in thesubstrate and a semiconductor chip is fixed to the bottom of the recess,it is possible to lower the height of the sealing member and thereforean electronic device such as a memory card can be made thin. Further,according to the construction wherein semiconductor chips are stacked inmultiple stages on the bottom of the recess, it is possible to diminishan increase in height of the sealing member. In the case where memorychips are stacked and fixed in two stages onto the bottom of the recess,it is possible, by adopting a wire lowering technique, to make theheight of the sealing member equal to that of the sealing member formedin case of fixing a memory chip in one stage onto the substrate.

(8) The closer to the front end in the inserting direction of the memorycard 1, the smaller the thickness of the memory card (the distance fromthe electrode surface to the cap surface) at the portion of externalelectrode terminals 8 b, so that it becomes easier to effect insertionand extraction of the memory card into and from a slot of the type whichgrips the electrode portion of the memory card with an elastic force.

SECOND EMBODIMENT

FIG. 22 is a plan view showing a back surface of a cap used in a memorycard according to another embodiment (second embodiment) of the presentinvention.

In this second embodiment, as shown in FIG. 22, slots 25 are radiallyformed respectively in corner portions of a shallow recess 3 a formed ina back surface 2 b of a cap 2. With such radial slots 25 formed incorner portions of the shallow recess 3 a of the cap 2, when thesubstrate 6 is bonded to the cap 2 through the adhesive 4, the slots 25guide the adhesive 4 into the shallow recess 3 a more uniformly, wherebythe bonding strength of the substrate 6 and the reliability of thebonding are improved.

THIRD EMBODIMENT

FIG. 23 is an exaggerated schematic sectional view of a memory cardaccording to a further embodiment (third embodiment) of the presentinvention.

In this third embodiment, as shown in FIG. 23, a slot 26 is formed in abottom of a shallow recess 3 a of a cap 2 so as to surround a deeprecess 3 b of the cap. The bottom portion of the shallow recess 3 alocated between the slot 26 and the deep recess 3 b is slightly lower,e.g., 40 to 70 μm lower, than the bottom portion of the shallow recesslocated outside the slot 26.

By thus forming the slot 26 in the bottom of the shallow recess 3 a ofthe cap so as to surround the deep recess 3 b, the adhesive 4overflowing from the deep recess 3 b can be allowed to stay within theslot 26 at the time of bonding the substrate 6 to the cap 2 through theadhesive 4. Consequently, the adhesive 4 does not leak to the exteriorof the cap 2 from peripheral edges of the substrate 6. Coupled with theeffects obtained in the first embodiment, a raised portion of theadhesive is no longer formed.

FOURTH EMBODIMENT

FIG. 24 is a bottom view of showing a back surface of a substrate havinga sealing member in a memory card according to a still furtherembodiment (fourth embodiment) of the present invention.

In this fourth embodiment, plural slots 27 which extend radially frominside to outside are formed in a surface of a sealing member 5 formedon a surface 6 a of a substrate 6, the surface of the sealing member 5confronting a bottom of a recess 3 (deep recess 3 b).

With the slots 27 formed radially in the surface of the sealing member5, when the substrate 6 is bonded to a cap 2 through the adhesive 4, theadhesive can be guided more uniformly not only into the deep recess 3 bbut also into the shallow recess 3 a, whereby the bonding strength ofthe substrate 6 and the reliability of the bonding are improved.

Although in the figure the slots 27 are formed at four corners of thesealing member 5, such slots may be formed also in side portions inaddition to the corner slots, whereby the adhesive 4 can be disperseduniformly throughout the whole of the outer periphery of the recess.

FIFTH EMBODIMENT

FIG. 25 is a plan view showing a back surface of a cap used in a memorycard according to a still further embodiment (fifth embodiment) of thepresent invention and FIG. 26 is a schematic sectional view showing inwhat state a substrate of the memory card is affixed to a cap.

As shown in FIG. 26, there sometimes occurs a case where resin portions(burrs) 30 a and 30 b remain in a sealing member 5 without being removedin portions of a shallow recess 3 a of the cap 2 which portionscorrespond respectively to a gate area and an air vent area of thesealing member 5 formed by transfer molding. In this fifth embodiment,in order to prevent contact of the resin portions (burrs) 30 a and 30 bwith an inner surface of a cap 2, recesses 31 a and 31 b are formed inportions of a shallow recess 3 a of the cap 2 which portions correspondrespectively to a gate area and an air vent area of the sealing memberformed by transfer molding.

That is, in the case where the sealing member 5 is formed by transfermolding, recesses 31 a and 31 b as relief recesses are formed in theshallow recess 3 a of the cap 2 at positions corresponding to a gatearea and an air vent area, and at the time of affixing the substrate 6to the cap 2, the resin portion 30 a which has cured in the gate areaand the resin portion 30 b which has cured in the air vent area, bothremaining in the sealing member 5, are prevented from contacting bottomsof the recesses 31 a and 31 b, thereby allowing the substrate 6 to bebonded positively to the adhesive 4. As a result, the substrate 6 isprevented from tilting and the yield is improved.

SIXTH EMBODIMENT

FIG. 27 is a plan view showing a back surface of a cap used in a memorycard according to a still further embodiment (sixth embodiment) of thepresent invention and FIG. 28 is a sectional view taken along line C-Cin FIG. 27.

This sixth embodiment has a construction in which a slot 26 is formed inthe bottom of the shallow recess 3 a of the cap in the third embodimentso as to surround the deep recess 3 b, allowing extra adhesive 4 flowingout from the deep recess 3 b to stay in the slot 26 and therebypreventing the extra adhesive 4 from flowing out to the exterior of thecap 2 past the peripheral edges of the substrate 6. The sixth embodimentalso has a construction in which recesses 31 a and 31 b are formed inthe shallow recess 3 a of the cap 2 used in the fifth embodiment,thereby permitting the substrate 6 to be bonded to the cap 2 positivelyeven with resin portions (burrs) 30 a and 30 b remaining in the sealingmember 5. With these constructions, the manufacturing yield for thememory card 1 is improved and it becomes possible to attain thereduction of cost.

The following is a brief description of effects obtained by typicalmodes of the present invention as disclosed herein.

(1) According to the structure wherein the substrate is affixed throughan adhesive to a recess formed in the back surface of the cap, it ispossible to provide an electronic device wherein substrate edges do notproject from the back surface of the cap, as well as a method ofmanufacturing the same.

(2) According to the structure wherein the substrate is affixed throughan adhesive to a recess formed in the back surface of the cap, it ispossible to provide a memory card wherein substrate edges do not projectfrom the back surface of the cap, as well as a method of manufacturingthe same.

(3) According to the structure wherein the substrate is affixed throughan adhesive to a recess formed in the back surface of the cap, it ispossible to provide an electronic device wherein the adhesive does notflow out to the back surface of the cap, as well as a method ofmanufacturing the same.

(4) According to the structure wherein the substrate is affixed throughan adhesive to a recess formed in the back surface of the cap, it ispossible to provide a memory card wherein the adhesive does not leak outto the back surface of the cap, as well as a method of manufacturing thesame.

INDUSTRIAL APPLICABILITY

Although the present invention has been described above concretely byway of embodiments thereof, it goes without saying that the invention isnot limited to the above embodiments, but that various changes may bemade within the scope not departing from the gist of the invention.

Although the present invention has been described above mainly aboutexamples in which the invention is applied to memory cards as abackground application field of the invention, it is needless to saythat the invention is also applicable to other electronic devices thanmemory cards. For example, the present invention is also applicable tosuch card products as ROM (Read Only Memory) card, RAM (Random AccessMemory) card, and IC card incorporating memory and CPU. Even in suchapplications there will be obtained the same effects as in the aboveembodiments.

The present invention is applicable at least to manufacturing electronicdevices of the structure wherein a substrate is fixed to a cap using anadhesive.

1. A method for a manufacturing a memory card comprising steps: (a)providing a substrate having wiring lines; (b) arranging a firstsemiconductor chip over a front surface of the substrate; (c) connectingthe first semiconductor chip and the wiring lines; (d) molding the firstsemiconductor chip by a resin; (e) providing a cap having a firstrecess; and (f) placing the molded first semiconductor chip and thefront surface of the substrate in the first recess; wherein, in the step(d), the substrate warps, and wherein, after the step (f), peripheraledges of the substrate is placed into the first recess and a centralportion of the substrate is placed out of the first recess.
 2. A methodfor a manufacturing a memory card according to the claim 1, thesubstrate warps such that the central portion of the substrate projectsin a direction away from the cap.
 3. A method for a manufacturing amemory card according to the claim 1, wherein a thermal expansioncoefficient of the resin is larger than that of the substrate.
 4. Amethod for a manufacturing a memory card according to the claim 1,wherein the resin has a thermal expansion coefficient in the range ofabout 9×10⁻⁶/° C. to about 16×10⁻⁶/° C., and wherein the substrate has athermal expansion coefficient in the range of 1.3×10⁻⁶/° C. to1.6×10⁻⁶/° C.
 5. A method for a manufacturing a memory card according tothe claim 4, wherein the substrate is formed of a glass fabric-basedepoxy resin.
 6. A method for a manufacturing a memory card according tothe claim 1, wherein, at the step (f), an adhesive is used.
 7. A methodfor a manufacturing a memory card according to the claim 1, wherein aplurality of electrode terminals are formed over the substrate, andwherein, after the step (c), the electrode terminals are electronicallyconnected to the first semiconductor chip.
 8. A method for amanufacturing a memory card according to the claim 1, wherein the memorycard further comprises a second semiconductor chip, wherein the firstand second semiconductor chips are a flash memory chip, respectively,and wherein the second semiconductor chip is stacked over the firstsemiconductor chip.
 9. A method for a manufacturing a memory cardaccording to the claim 1, wherein the memory card further comprises athird semiconductor chip, wherein the first semiconductor chip is aflash memory chip, and wherein the third semiconductor chip is acontroller chip for the flash memory chip.
 10. A method for amanufacturing a memory card according to the claim 1, wherein a planarsize of the memory card is a planer size of defined by the multi mediacard standard.
 11. A method for a manufacturing a memory card comprisingsteps: (a) providing a substrate; (b) arranging a first semiconductorchip over a front surface of the substrate; (c) molding the firstsemiconductor chip by a resin; (d) providing a case having a mainsurface and a back surface, and the back surface of the cabin has afirst recess; (e) placing the resin and the front surface of thesubstrate in the first recess; wherein, in the step (c), the substratewarps, and wherein, after the step (e), the distance between a centralportion of the substrate and the main surface of the case is greaterthan the distance between an edge portion of the substrate and the mainsurface of the case.
 12. A method for a manufacturing a memory cardaccording to the claim 11, the substrate warps such that the centralportion of the substrate projects in a direction away from the case. 13.A method for a manufacturing a memory card according to the claim 11,wherein a thermal expansion coefficient of the resin is larger than thatof the substrate.
 14. A method for a manufacturing a memory cardaccording to the claim 11, wherein the resin has a thermal expansioncoefficient in the range of about 9×10⁻⁶/° C. to about 16×10⁻⁶/° C., andwherein the substrate has a thermal expansion coefficient in the rangeof 1.3×10⁻⁶/° C. to 1.6×10⁻⁶/° C.
 15. A method for a manufacturing amemory card according to the claim 14, wherein the substrate is formedof a glass fabric-based epoxy resin.
 16. A method for a manufacturing amemory card according to the claim 11, wherein, at the step (e), anadhesive is used.
 17. A method for a manufacturing a memory cardaccording to the claim 11, wherein a plurality of electrode terminalsare formed over the substrate, and the electrode terminals areelectrically connected to the first semiconductor chip.
 18. A method fora manufacturing a memory card according to the claim 11, wherein thememory card further comprises a second semiconductor chip, wherein thefirst and second semiconductor chips are a flash memory chip,respectively, and wherein the second semiconductor chip is stacked overthe first semiconductor chip.
 19. A method for a manufacturing a memorycard according to the claim 11, wherein the memory card furthercomprises a third semiconductor chip, wherein the first semiconductorchip is a flash memory chip, and wherein the third semiconductor chip isa controller chip for the flash memory chip.
 20. A method for amanufacturing a memory card according to the claim 11, wherein a planarsize of the memory card is a planer size of defined by the multi mediacard standard.
 21. A method for a manufacturing a memory card comprisingsteps: (a) providing a substrate; (b) mounting a first semiconductorchip over a front surface of the substrate; (c) molding the firstsemiconductor chip by a resin; (d) providing a case having a mainsurface and a back surface, and the back surface of the case has a firstrecess and a second recess; (e) covering the resin and the front surfaceof the substrate by the case; wherein the depth of the first recess isdeeper than the depth of the second recess, wherein the resin is fittedin the first recess, wherein an edge portion of the substrate is fittedin the second recess, and wherein, in the step (c), the substrate warpsso that a central portion of the substrate projects in a direction awayfrom the case.
 22. A method for a manufacturing memory card according tothe claim 21, wherein the edge portion of the substrate is put incontact with the bottom of the second recess.
 23. A method for amanufacturing a memory card according to the claim 21, wherein a thermalexpansion coefficient of the resin is larger than that of the substrate.24. A method for a manufacturing a memory card according to the claim21, wherein the resin has a thermal expansion coefficient in the rangeof about 9×10⁻⁶/° C. to about 16×10−⁶/° C. wherein the substrate has athermal expansion coefficient in the range of about 1.3×10−⁶/° C. to1.6×10−⁶/° C.
 25. A method for a manufacturing a memory card accordingto the claim 24, wherein the substrate is formed of a glass fabric-basedepoxy resin.
 26. A method for manufacturing a memory card according tothe claim 21, wherein, at the step (e), an adhesive is used.
 27. Amethod for a manufacturing a memory card according to the claim 21,wherein a plurality of electrode terminals are formed over thesubstrate, and the electrode terminals are electrically connected to thefirst semiconductor chip.
 28. A method for a manufacturing a memory cardaccording to the claim 21, wherein the memory card further comprises asecond semiconductor chip, wherein the first and second semiconductorchips are a flash memory chip, respectively, and wherein the secondsemiconductor chip is stacked over the first semiconductor chip.
 29. Amethod for a manufacturing a memory card according to the claim 21,wherein the memory card further comprises a third semiconductor chip,wherein the first semiconductor chip is a flash memory chip, and whereinthe third semiconductor chip is a controller chip for the flash memorychip.
 30. A method for a manufacturing a memory card according to theclaim 21, wherein a planar size of the memory card is a planer size ofdefined by the multi media card standard.
 31. A method for amanufacturing a memory card comprising steps: (a) providing a substrate;(b) mounting a first semiconductor chip over a front surface of thesubstrate; (c) molding the first semiconductor chip by a resin; (d)providing a case having a main surface and a back surface, and the backsurface of the case has a first recess and a second recess; (e) coveringthe resin and the front surface of the substrate by the case; whereinthe depth of the first recess is deeper than the depth of the secondrecess, wherein the resin is fitted in the first recess, wherein an edgeportion of the substrate is fitted in the second recess, and wherein, athermal expansion coefficient of said sealing member is larger than thatof said substrate.
 32. A method for a manufacturing a memory cardaccording to the claim 31, wherein the edge portion of the substrate isput in contact with the bottom of the second recess.
 33. A method for amanufacturing a memory card according to the claim 31, wherein the resinhas a thermal expansion coefficient in the range of about 9×10⁻⁶/° C. toabout 16×10−⁶/° C. wherein the substrate has a thermal expansioncoefficient in the range of about 1.3×10−⁶/° C. to 1.6×10−⁶/° C.
 34. Amethod for a manufacturing a memory card according to the claim 33,wherein the substance is formed of a glass fabric-based epoxy resin. 35.A method for a manufacturing a memory card according to the claim 31,wherein, at the step (e), an adhesive is used.
 36. A method for amanufacturing a memory card according to the claim 31, wherein aplurality of electrode terminals are formed over the substrate, and theelectrode terminals are electrically connected to the firstsemiconductor chip.
 37. A method for a manufacturing a memory cardaccording to the claim 31, wherein the memory card further comprises asecond semiconductor chip. wherein the first and second semiconductorchips are a flash memory chip, respectively, and wherein the secondsemiconductor chip is stacked over the first semiconductor chip.
 38. Amethod for a manufacturing a memory card according to the claim 31,wherein the memory card further comprises a third semiconductor chip,wherein the first semiconductor chip is a flash memory chip, and whereinthe third semiconductor chip is a controller chip for the flash memorychip.
 39. A method for a manufacturing a memory card according to theclaim 31, wherein a planar size of the memory card is a planer size ofdefined by the multi media card standard.